Compaction machines are used at landfill sites to crush and compact waste material deposited at such locations. These self propelled machines usually have three or four large driving wheels with inverted V shaped cleats mounted on their rims, the cleats being staggered around the periphery of the rims, generally with the axes of the cleats parallel to the axles of the wheels. As the wheels are rotated during the traverse of the machine over a path in the landfill, the cleats crunch into the material being compacted and unless encountering some solid substance, the crests of the cleats sink into the bed until the rims are supported thereby. Repeated passes crush and devoid the waste material increasing the density and aiding in its ultimate deterioration.
Considerable effort has been expended in developing the contour and construction of cleats to make them more effective in the crushing compaction of waste. Because of the abrasiveness of some of the materials dumped on the landfill, and the nature of the service, cleats tend to wear out rapidly requiring their replacement if the compactor is to retain its efficiency. A design of cleat invented by my coworker, Maurice J. Trainer and myself, and disclosed in U.S. Pat. No. 3,891,341 issued June 24, 1975, has been found to provide increased wear life, at least over many other forms of cleat used for this purpose. According to this patent, the radially outward corners of the converging faces of the cleat are enlarged, so that the outer cutting edge presents a "dog-bone" shape, which minimizes wear which would otherwise occur on the ends of this working face. The crests of cleats of this construction are parallel to the axle of the wheel and are usually welded to the rim and arranged in diagonal rows. When replacement is required, the welds are burned off and new cleats are welded in the same positions.
It has also been the practice to make the cleats in two pieces with the inner portion or base welded to the wheel and the outer, wearing portion connected to the base either by bolts or welding. These removable cleats have been used extensively on so-called "sheeps foot" rollers, used to compact surfaces such as road beds prior to paving. An example of one of this replaceable type of feet is disclosed in U.S. Pat. No. 3,274,908 issued Sept. 27, 1966. Here the replacable or cover element is held by a pin or bolt extending through the base; this pin in turn is held against endwise movement by a detent pressing against the central portion of the pin. The advantage of course in such a cleat is that the wear portion can be more easily removed and replaced than a solid cleat which is welded to the rim. Considering the large number of cleats (upwards of one hundred) that require replacement, on one wheel alone, the saving in time, using a two piece construction, is very considerable.